BQ2: What are the principles and applications of quantum physics?

A revolution in our understanding of quantum mechanics and its applications is shaping the future of fundamental science and engineering. Quantum physics determines the ultimate miniaturization scale and operating principles of nano-devices that function at single electron, single spin, single molecule, or single photon levels. The full range of phenomena permitted by the principles of quantum mechanics is coming to be understood only now, a century after its original discovery. New techniques are directly probing such cornerstones of quantum physics as quantum entanglement and quantum measurement. Quantum information processing – relying on entangled states of many particles – pushes the limits of our present experimental, theoretical and computational approaches. One of the challenges here is to control the interaction of these complex systems with their environments, which induce decoherence and dephasing; these processes generate the transition from the quantum-mechanical microscopic world to the classical macroscopic world. Yet another line of inquiry is leading to new materials with dramatic properties – graphene, topological insulators, and spin liquids, for instance.

Physicists at Duke are developing means of quantum information processing, studying nonlinear interaction between matter and light, investigating transport of charge and spin in nanostructures, and examining emergent behavior in interacting quantum systems, both in equilibrium and far from equilibrium. Some specific subjects of study include atomic and superconducting qubits; sub-diffraction limit optics and “spintronics” and electronic transport in molecules, graphene, and quantum nanostructures; and the search for exotic phases of matter and quantum phase transitions.